The synthesis of terpenes is a large field of research that is woven deeply into the history of chemistry. Terpene biosynthesis is a case-study of how the logic of a modular design can lead to diverse structures with unparalleled efficiency. This work mimics Nature by leveraging modern Ni-catalyzed electrochemical sp2–sp3 decarboxylative coupling reactions—enabled by Ag-nanoparticle modified electrodes—to intuitively assemble terpene natural products and complex polyenes. The step-change in efficiency of this approach is exemplified through the scalable preparation of 13 complex terpenes, which minimized protecting group manipulations, functional group interconversions, and redox fluctuations. Finally, the mechanistic aspects of the essential functionalized electrodes are studied in depth through a variety of spectroscopic and analytical techniques.